Apparatus for convolution of thread or yarn filaments



Aug; 12, 1969 EN'SSUN ET AL 3,460,213

APPARATUS FOR CONVOLUTION OF THREAD OR YARN FILAMENTS Filed Jan. 22, 1968 2 Sheets-Sheet 1 FIG. I 4 2 AIR CONSUMPTION GAP LENGTH- INVENTORS:

KURT ENSSLIN PETER HEINEN JOSEF RONGEN wwwww w ATT'YS Aug. 12, 1969 ENS'SUN ET AL 3,460,213

APPARATUS FOR CONVOLUTION OF THREAD OR YARN FILAMENTS Filed Jan. 22, 1968 2 Sheets-Sheet 2' FIG. 4b

FIG. 4c

'lllll FIG; 5 23 HQ 6 @FEED SPOOL INVENTORS:

KURT ENSSLIN PE ER HEINEN JOSEF RONGEN ATT'YS United States Patent U.S. Cl. 281.4 30 Claims ABSTRACT OF THE DISCLOSURE Improved apparatus for the convolution of the individual filaments of at least one multifilarnent thread or yarn by means of an air jet wherein a shaped body has a thread channel or passageway therethrough and a nozzle bore for the jet of air entering one side of the thread channel with a bafile chamber or bored opening coaxial with the nozzle bore on the opposite side of the thread channel. The treatment of the thread or yarn is improved and a reduction in the consumption of air is achieved provided that certain limitations in the dimensions of various parts are strictly observed, e.g. the diameter of the nozzle bore should be at least equal to or greater than the diameter of the baffle chamber, and the sum of the depth of the baflle chamber and the height of the thread channel corresponding to its diameter at the jet zone should be at least about 2.2 times the smallest diameter of the baffle chamber. The diameter of the thread channel should be sufliciently small over at least a portion of its length, however, to prevent the thread which is being treated from completely being driven out of the path of the air jet. Another improvement includes a spiral or helical partition of the jet nozzle bore. Still another variation includes means to flatten the thread or yarn just before it enters the thread channel. Other improvements and modifications are described herein.

This invention is concerned with an apparatus or device for the whorling or formation of convolutions of the individual filaments of a multifilament thread, yarn or the like by means of a rapidly flowing fluid medium such as a jet of air which impinges on the thread or yarn as it is conducted approximately perpendicularly to the jet of air. This type of thread treatment is sometimes referred to as a texturizing or bulking operation wherein the individual filaments become displaced or convoluted from their generally linear orientation while avoiding as much as possible the formation of snarls or knotted loops in the thread or yarn. The convolutions of the filament represent a somewhat random whorling, twisting or similar disarrangement of the individual filaments into non-parallel relationships with each other so that a certain degree of entanglement and fore shortening of the length of thread occurs together with some increase in its cross-sectional volume.

In particular, the present invention is concerned with the type of apparatus through which the thread to be treated is drawn and in which it is conducted for a short period of time between a nozzle through which the jet of air or other fluid is expelled and a baifle chamber or socalled resonance chamber opposite the exit of the nozzle and substantially located on the same axis as the nozzle.

It is known from German Auslegeschrift No. 1,214,825 that a multifilament thread can be whorled or convoluted under tension or pressure by an air jet issuing from a nozzle with high velocity. The devices suggested for carry- 3,460,213 Patented Aug. 12, 1969 "ice ing out this process exhibit bores, grooves, slots or the like which serve as a thread conduit wherein the thread runs along the longitudinal axis. In this thread conduit, the thread is blown or blasted by one or more nozzles which can be arranged in various ways.

Another device useful for this type of thread treatment is described in Canadian Patent No. 554,150. In this case, the thread is conducted through a blast jet which emerges from a nozzle and impinges on a so-called resonance chamber opposite the nozzle opening. U.S. Patent No. 3,026,597 also described a jet nozzle with an enlargement of the thread channel at the entry of the jet nozzle that can be described as a turbulence chamber.

These previously known processes and devices produce a thread or yarn whose increase in volume per unit length is relatively slight in comparison to the initial untreated thread or yarn. The consistency or coherence of the yarn is improved on account of the entanglement of the individual filaments as well as yielding a certain texturizing effect. A measure of the degree of entanglement is the size of the so-called gap lengths. This size or measurement specifies the gap distance over which a needle or pin inserted into the yarn perpendicularly to the thread axis can be moved longitudinally up to the point at which fiber entanglement collects or dams up in front of the needle so as to prevent any further relative movement between the needle and the yarn. The shorter this gap length is, the higher is the degree of entanglement of the individual filaments in the yarn. A high degree of texturizing is therefore evidenced by a very short gap length.

As the fluid jet medium for the thread treatment, compressed air has generally proven to be especially suitable. It is of course possible to use other gaseous or fluid media in place of air. ;Even with air, it is disadvantageous that the production of compressed air is relatively expensive, and in addition, when used for the treatment of thread to be employed in high quality textiles, there are especially high requirements on the purity of the air which further increases its expense. Experiments have shown that previous devices known for texturizing or entangling thread exhibit an undesirably high air consumption so that the industrial or commercial use of the process can be placed in question.

It is therefore an object of the present invention to provide a device for the convolution of the individual filaments of the thread or yarn wherein the intensity of the jet action of the turbulent or whorling fluid medium can be increased and wherein the amount of air consumed during the thread treatment can be decreased when achieving a desired thread closeness or so-called gap length. It is also an object of the invention to provide an improved apparatus which forms the entanglement or convolutions of the filaments in the treated thread in an especially advantageous and uniform manner. Yet another object of the invention is to provide apparatus for the texturizing of thread yarn which is capable of producing a much higher degree of entanglement and which is adaptable to a great variety of threads or yarns. These and other objects and advantages of the invention will become more apparent upon consideration of the following detailed disclosure.

In accordance with the invention, it has now been found that a substantial improvement in the thread treatment is possible by observing certain limitations for the dimensions of the essential components of the apparatus which generally comprises a shaped body containing an elongated thread conducting channel therethrough, a jet channel as a nozzle for directing fluid under pressure'into the thread conducting channel from one side thereof, and a baffle chamber coaxial with the jet channel on the opposite side of the thread channel, so as to provide a turbulent jet zone within the shaped body at the conjunction of the thread channel, the jet channel and the baifie chamber. In particular, it is essential that the jet channel has a cross-sectional dimension at least equal to or greater than the corresponding cross-sectional dimension of the bafile chamber, and the sum of the depth of the bafiie chamber and the height of the thread conducting channel at the turbulent zone measured in the axis of the baflie chamber must be at least about 2.2 times the smallest cross-sectional dimension of the baflle chamber.

Above all, it has proven that the presence of a resonance chamber, designated herein as a baffle chamber, is in fact quite desirable in any thread whorling or texturizing process. It is obvious that the obtainable resonance phenomenon or the self-regulating air baflie causes especially favorable conditions for this type of thread treatment. However, in the known device according to Canadian Patent No. 554,150, the fluid jet medium flows very easily out of the treatment zone of the device so that it is not available for the thread treatment. Likewise, a similar loss of the fluid jet medium occurs in the device according to US. Patent No. 3,026,597. In this case, the only means for transporting the thread is the air stream flowing out of the turbulent chamber and exhausting in the major portion through the larger end of the thread passageway so as to feed the yarn through the passage. Under these circumstances, the air must therefore flow out of the turbulent chamber into the free atmosphere with a great velocity. The energy gradient of the fluid jet medium between the jet channel and the outer air can thus be used only in part for the texturing of the thread in the turbulence chamber, so that in this case the degree of efficiency of energy being introduced for texturing of yarn is also very slight, especially as the efficiency of the turbulence chamber is not satisfactory when entangling a multifilament yarn.

Thus, while the present invention recognizes the essential desirability of a bafl le chamber arrangement together with a jet channel or nozzle and a thread channel or passageway, it has been surprisingly found that this type of device can only function with efficiency when following the prescribed limitations set forth herein. For example, it is also especially desirable to employ a thread channel or passageway having the same cross-sectional dimension of diameter over both the entrance into and the exit from the turbulent zone where the jet treatment occurs. In any event, the exit portion of the thread channel should not be noticeably larger than the entry portion of this channel. As described in greater detail below, it is feasible to enlarge the cross-sectional dimension or diameter of the entry or feed portion of the thread channel provided that other essential limitations are observed.

The thread conducting channel is preferably about perpendicular to the common axis of the jet channel and the baffle chamber. Although the feed or entry portion of the thread channel may be enlarged with reference to the exit portion of this channel, as noted above, a further enlargement of the thread channel in the turbulent jet zone is preferably avoided, and the jet channel should likewise extend directly to the turbulent jet zone without any enlargement of its diameter at this point. Thus, in all of the preferred constructions, the turbulent jet zone is preferably defined by the volume corresponding to the cylindrical or columnar projection of the jet channel across the thread conducting channel or passageway with the mouth or outlet opening of the jet channel being at a sharp angle with the thread passageway.

A particularly preferred and especially effective device is characterized by the fact that the cross-sectional dimension of the jet channel for the emerging fluid jet is equal to one to two times the corresponding dimension of the baflie chamber. The sum of the baflie chamber depth and the height of the thread conducting channel in the turbulent zone is preferably equal to 2.5 to times the smallest cross-sectional measurement of the bafile cham her in all of the devices according to the invention.

Experiments comparing the thread treatment as between the known devices and the apparatus of the invention have shown that the latter requires considerably less air for the production of yarn with an equal degree of entanglement, i.e. equal gap lengths. Furthermore, the entanglement or degree of texturizing could be still considerably increased by raising the air pressure into a range capable of producing smaller gap lengths. This additional increase of entanglement or production of smaller gap lengths does not occur with the known devices even at a higher air consumption.

If the baffle chamber is less deep than prescribed herein, then the effect to be obtained by its coaxial arrangement with the jet channel definitely declines. An excess depth of the bathe chamber beyond a certain point is ineffective with respect to any further improvement of the thread treatment. In order to maintain the dimensions of the device as small as possible, the sum of the baffle chamber depth and the height of the thread conducting channel should therefore correspond to about 3 to 5 times the smallest cross-sectional dimension of the baflile chamber. In any given case, a substantial reduction of the turbulent jet or whorling effect results if the jet channel diameter is detectably smaller than the diameter of the baffle chamber.

The length of the thread channel or passageway in the device should be at least 3 times as long as the smallest cross-sectional dimension of the baffle chamber. In order to maintain the dimensions of the device as small as possible, it is not advisable to permit the length of the thread channel to exceed 30 times this value. In general, it is most preferable to provide a thread channel length of about 5 to 20 times the smallest baflie chamber crosssectional dimension.

It is advantageous if the cross-section of both the jet channel and the baffle chamber are circular in shape. However, a rectangular, oval or other shape is likewise possible. In order to prevent a temporary deviation of the thread from the jet stream, th width of the thread conducting channel or bore, measured perpendicular to the jet channel axis, i.e. transverse to the direction of thread travel, should be about equal to the sum of the jet channel width and two times the diameter of the thread, yarn or filaments being treated. Thereby the ratio of the cross-sectional area of the thread passageway to that of the jet channel should amount to about 1.5 :l to 21:1. By conforming the thread conducting channel to these dimensions, the result is achieved that the thread runs steadily in the jet stream, because even if it sometimes rests on the inner wall of the thread conducting channel, it still is not entirely driven out from the jet stream. Tests conducted with previously known devices have shown that the thread as extended therein does not actually run in the jet stream. This unfavorable behavior of the thread essentially requires an increase in the pressure of the compressed air or other jet fluid. Thus, in prior devices, th degree of entanglement and thereby the deformation or convolutions brought into the thread per unit volume of the fluid jet medium have been very slight in proportion to the air consumption. By comparison, if the device is constructed in accordance with the present invention while making certain that the width of the thread passageway perpendicular to the jet channel axis is sufficiently small, the thread does remain in the jet stream throughout its treatment so as to further decrease the amount of air required.

The invention is further described and illustrated with the aid of the following drawings wherein:

FIG. 1 is a horizontal cross-sectional view taken through the longitudinal axis of the jet channel in order to illustrate one embodiment of the invention in which the essential jet channel, thread channel and baffle chamber are formed in a cylindrical insert fitting into a separate housing;

FIG. 2 is a vertical cross-sectional view of the same device as shown in FIG. 1 so as to provide a cross-sectional view along the longitudinal axis of the cylindrical insert;

FIG. 3 is a graph illustrating the relationship of air consumption and gap length as between the device of the present invention and two prior devices;

FIG. 4 is a bottom perspective view with the lower section of the device cut off along the longitudinal axis of the jet channel and battle chamber, thereby illustrating a preferred insertable member in the jet channel;

FIGS. 4a, b, c and d are cross-sectional views of the central portion of the device shown in FIG. 4 taken on line 4-4, i.e. looking into the mouth of the jet channel from the thread conducting channel;

FIG. 5 is a vertical cross-sectional view of still another embodiment of the device according to the invention, including rods or pins for pretreatment of the thread;

FIG. 6 illustrates still another embodiment of the invention in a vertical cross-sectional view;

FIG. 7 is a vertical cross-sectional view of yet another embodiment of the invention; and

FIG. 8 is a side view, partly in cross-section of an especially preferred construction and arrangement for mounting and using the device of the invention.

Referring first to FIGS. 1 and 2, the shaped cylindrical block or insert 1 contains a vertical thread passageway or conducting bore 2 having a uniform diameter throughout. This insert 1 is firmly seated in a rectangular housing 3 which contains a threaded conduit 4 connected to the feed pipe 5 for the supply of compressed air or other fluid medium which is then conducted to the cylindrical jet channel or nozzle 6 arranged perpendicularly to the axis of the thread channel 2. The baflle chamber 7 represents a continuation of the nozzle bore 6, and in this embodiment, the baffle chamber has the same diameter and the same length as the jet channel in the cylindrical insert 1. With this arrangement, various cylindrical inserts 1 can be designed for different threads or yarns such that one insert can be readily replaced by another. The remaining parts of the apparatus can then remain substantially the same in all cases.

The thread T runs approximately along the axis of the thread passageway 2 through the device during its operation, and is drawn onto a take-up spool (FIG. 8) while being maintained under a minimum tension of preferably at least about 0.02 gram/denier.

The fluid working medium, e.g. compressed air, enters through the feed conduit 4 into the jet channel or nozzle 6 and emerges as a jet stream in the thread channel 2. At the intersection of the thread channel axis and the jet channel axis, i.e. in the region surrounding point 8, the thread T runs through the jet stream of the compressed air and is subjected to the turbulent or whorling action of the air. Especially good results have been achieved with this particular arrangement or similar devices when constructed in accordance with the invention such that: the diameter of the thread channel at the turbulent zone defined by the emerging jet stream, i.e. transversely of the thread channel at the jet point, is equal to 1.1 to 1.8 times the diameter of the baffle chambers; the length of the entire thread channel equals 10 to 30 times the diameter of the bafiie chamber; the jet channel diameter equals 1 to 1.2 times the baffle chamber diameter; the length of the jet channel equals about 1.6 to 4, preferably 2 to 2.8, times the bafile chamber diameter; the distance between the mouth of the jet channel and the base of the bafile chamber, i.e. taking the sum of the depth of the bafiie chamber and the height of the cylindical part of the thread conducting channel, is equal in measurement to at least 2.2 times the bafiie chamber diameter; and the baffle chamber diameter itself has a value of about 0.6 to 4 mm.

In FIG. 3, the so-called gap length of the treated thread is shown in relationship to the air consumption required for any particular gap length. The different curves were obtained by comparative tests with different devices. Curve A corresponds to the values achieved with the device shown in German Auslegeschrift No. 1,214,825. Curve B correspondes to the results achieved with a device as shown in the figure of the Canadian Patent No. 554,150, while the Curve C illustrates the values achieved with the device of the present invention. A comparison of these three curves as obtained with different texturizing devices clearly shows the pronounced improvement and efiiciency in air consumption with the device of the present invention. Thus, considerably shorter gap lengths are achieved than with the prior devices even though the air consumption is substantially increased in these prior devices.

With the invention, it has thus been established that with just one jet channel or nozzle per thread, one achieves a very high degree of convolution of the individual filaments or desired entanglement in almost all cases, i.e. with the most diverse types of threads or yarns. It is of course suitable in the case of threads or yarns with heavy individual titers, i.e. of relatively large individual denier, to improve the texturizing effect by arranging two or more jet channels or nozzles one after the other for each thread or yarn being treated.

It has thus been found that the apparatus according to the invention is applicable to all known multifilament threads and also so-called fibrous yarns in order to achieve an excellent texturizing effect. The fibrous yarns do require, however, a slight twisting since they usually do not have sufficient cohesion and cannot be easily conducted through the device of the invention. In particular, there can be treated all types of filaments as produced from synthetic, high molecular weight polymers such as polyamides, polyesters and the like. The various nylon filaments or those of polyethylene terephthalate are especially preferred because of their relatively high strength which permits them to endure quite well the stresses placed on the filaments in the jet stream without damaging them or decreasing their mechanical or textile properties. It is understood, of course, that the filaments of two or more threads or even several monofilaments can be whorled or convoluted with each other with at least one jet nozzle, provided that there is a corresponding adjustment of the thread channel diameter.

According to an especially preferred embodiment of the device according to invention, the jet channel or nozzle or at least the terminal portion thereof contains one or several flushly fitted screw-shaped or corkscrew type inserts preferably produced from metal twisted about its longitudinal axis. Such helically or spirally twisted inserts partition the jet channel into two or more spiral shaped channels running along side each other with the same angle of twist. This partition need not proceed completely through the nozzle, and if desired, the metal strip can contain cut-out portions or slits as bafiles or the like to increase the turbulence of the flowing air. Also, these inserts can be placed so as to run only along the walls of the jet channel and/or its adjacent feed channel so that these walls are shaped somewhat as in a rifled gun barrel. Such inserts can be fastened with the aid of any conventional means tightly to the tubular wall or they may preferably be removably mounted as loose metal strips. As much as possible, the insert should exhibit a half winding. With too slight a twist, the effectiveness of the device diminishes, and the maximum number of possible windings is limited primarily by its angle of pitch or the exit angle of the individual streams with reference to the axis of the jet channel. Inserts with up to as many as two windings have acted especially well. The surprising effect of these inserts can be varied if the partitions or dividing walls formed between the twisting channels are varied in their position with respect to the thread channel axis, i.e. so that the end of the insert terminating at the mouth of the jet channel is turned into various positions.

This special embodiment, which obviously permits the jet medium to strike or impinge on the thread in various different ways, has proven to be especially valuable in the jet treatment of carpet yarns, i.e. multifilament yarns of about 500 denier and higher. With the correct choice of the other limitations according to the invention such as the jet nozzle, yarn speed, nozzle dimensions, number of windings on the insert and position of the end of the insert, it is possible to obtain a yarn in which the convoluted filaments do not draw into relatively sharply defined knots or nodules as occurs in previously known devices. Instead, nodular points are formed with a rather obscured blending into the normally observed interspaces or gaps between the individual nodules.

A simple device according to this special embodiment of the invention is illustrated in FIG. 4. In the jet channel 6, there is placed an insert 9 which consists of a spiralshaped metal strip. By suitably broadening or providing cars 10 on the outer end of this strip 9, these ears or extensions can be inserted into corresponding slots (not shown) in the housing 1 or other suitable supporting means. This serves to hold the insert against slipping lengthwise as well as against twisting under the influence of the compressed air. Other means of mounting such metal strips will be readily apparent to any skilled mechanic. FIGS. 4a to 4d show various positions of the terminal end 11 o fthe insert 9 where it appears approximately flush with the thread conducting channel 2. Thus, in FIG. 4a, the longitudinal dimension of the facing end 11 of the insert is parallel to the axis of the thread conducting chamber, i.e. substantially parallel to the thread itself. In FIG. 4b, a second insert 12 is shown in broken lines while the first insert 11 has been rotated so as to be in a position transverse to the thread channel axis. This double insert forms a single cross-shaped crosssection at each point along the jet channel axis with the angle between the sides or shanks being 90. FIGS. 40 and 4d indicate still other positions of the single insert with respect to its terminal end 11. In general, the number of twists of the spiral metal strip preferably lies between one-half and two over the length of the jet channel.

Another especially suitable arrangement of the device according to the invention is illustrated in the special embodiment shown in FIG. 5. From the point at which the thread enters the device up to about the point at which the compressed gas stream flowing in through the jet channel 13 coaxial with'the bafiie chamber bore 14 meets with the running thread, there is an entry or feed section 15 of the thread conducting channel which continuously narrows or constricts in the form of a conical section, and the exit or remaining portion 16 of the thread channel then further leads in the direction of thread travel as viewed from the point of juncture 17 as a cylinder having a uniform diameter. The passageway is preferably polished and free of any sharp edges or corners.

Devices of this type which have proven especially effective are those whose thread conducting channel at the thread entranceexhibit a diameter of 1.5 to 5 times the baflie chamber diameter and then constricts conically up to 1.1 to 1.8 times the bafiie chamber diameter. A well smoothed passageway is particularly desirable at about the point of the cone in the cylindrical bore or outlet section 16 of the thread channel, i.e. in that region at which the axis of the thread conducting channel or bore and the axis of the jet channel or bore and its coaxial baflle chamber intersect with each other.

Another preferred embodiment which is particularly distinguished by its reduced air consumption is further set forth in FIG. 6. This device contains a thread conducting channel which consists of a cylindrical feed or entry section 18 which extends up to directly behind the entry mouth of the jet channel 19, and the thread channel then continues as a considerably narrower cylindrical section 20 from which the thread emerges. With otherwise constant dimensions, it has been shown that this arrangement of the thread channel yields an especially advantageous effect if the constriction of thethread channel or bore behind the jet point or turbulent jet zone amounts to about 15-60%, especially -45%. For example, it was found to be possible by constricting the thread channel exit or run-out portion from 2.6 down to 1.4 mm., or from 2.1 down to 1.1 mm., it was possible to decrease the jet pressure from 2.5 atmospheres to 1.7 atmospheres while still achieving the same average gap length. Since it is known that the outwardly flowing amount of 'gas in its free outflow or escape at the speed of sound is proportional to the factor /p wherein p is the jet pressure at the entrance int-o the jet channel and p2 is the density of the air jet at the pressure p it will be apparent that the reduction of the amount of air required is quite considerable.

In the particular device according to FIG. 6, it is still essential that the proportions or dimensions of the thread channel cross-section at the turbulent zone must still lie within the ranges given for this invention. In addition, the passageway or transition from the larger entry channel 18 to the smaller diameter of the exit channel 20 is of great importance. Especially with reference to the uniformity of the thread properties, it has been apparent that a very smooth, well rounded off passageway is necessary such that the rounded or finished ofl? radius is made about equal to 2 to 5 times the value of the thread channel diameter at the thread entry section. This larger thread channel diameter thus corresponds preferably to 1.1 to 1.8 times the baflie chamber diameter. When working with heavy threads or yarns having a thick denier and/or when using the device described below for the flattening of the thread into a small band or ribbon prior to the thread entry, it is helpful to design the feed portion of the thread channel, i.e. up to about the vicinity of the jet point or turbulent jet zone, into a conical shape. In this case the said larger thread channel diameter covers only this zone.

In addition, the passageway or transition between the larger diameter channel 18 and the smaller diameter channel 20 is preferably formed as a beveled or conically shaped constriction 21 with an angle of aperture of 20 to preferably in the neighborhood of approximately 60. The beginning of this conical constriction from the axis of the jet channel 19, in this case at its mouth or entry into the thread conducting channel 18, is displaced as viewed in the direction of thread travel at least about a jet channel radius. In other words, the constriction essentially begins after the jet point or the point at which the axes of the intersecting channels meet. Especially with so-called textile titers, i.e. titers up to about 200 to 300 denier, the diameter of the thread conducting channel in the thread exit section can amount to about 0.8 to 1.8 mm., preferably 1.0 to 1.4 mm.

Furthermore, it has been surprisingly shown that the uniformity of dyeing in the individual jet-formed nodules or knots, which normally tend to be subjected to so-called spray dyeing, can be considerably improved if the thread just before its entry into the thread channel is spread out into a small flat band or ribbon and only then brought into the nozzles such that the jet stream impinges perpendicularly into the flat band surface. In this case, there is arranged shortly before the thread entry of the jet device, suitable means for broadening out the thread into a small band having the desired form. Such flattening means can consist of two parallel cylindrical rolls, rods or pins 23 which are similar to a simple grid thread brake, e.g. as illustrated in FIG. 5. This simple flattening means is preferably arranged so that the axis of the thread channel is tangential to the surfaces of both of the thread guiding pins or rods arranged one after the other, such that both of the small pins lie with theiraxes parallel to each other and moreover perpendicular to the plane through the axis of the thread channel and the common axis of the jet channel 13 and the baflie chamber bore 14. The cylindrical pins for flattening the thread preferably have a gap interval or spaced distance between themselves of 0.3 to 3 mm., preferably 0.8 to 2.5 mm. In other words, the pins do not pinch the thread between them but provide tangential pressure on opposite sides of the thread in sequence so as to flatten the band just before it enters into the thread channel of the jet device. In any individual case, the distance between the two pins is essentially dependent upon the total titer and number of filaments in the thread or yarn. The diameter of the cylindrical pins advantageously lies between 0.6 to 3 mm., preferably between 0.8 and 2 mm. The distance of the pin-shaped thread guide from the thread channel axis is thus preferably equal to the cross-sectional radius of the small pins forming the thread guide. This means for flattening the thread to a small band should be positioned as closely as possible for the entry into the thread conducting channel of the jet device. A distance of abuot 3 to 15 mm. and especially 5 to 12 mm. for the closest pin guide has proven to be especially satisfactory.

Still another embodiment of the jet channel in the device of the invention is shown in FIG. 7. This embodiment also contains a cylindrical thread conducting channel 24, a similar cylindrical jet channel 25, and a bafiie chamber 26 which is also cylindrical and arranged coaxially with the jet channel on the opposite side of the thread conducting channel. This embodiment is characterized by the fact, however, that the axis of the jet channel and baffle chamber is inclined against the direction of thread travel and in fact engages the axis of the thread conducting channel or bore at an angle 27 which is smaller than 90 but greater than 60. This angle preferably lies between about 60 and 75. In FIG. 7, the thread thus runs from top to bottom since it has been proven that the best effect occurs if the velocity components of the jet stream appearing in the axis of the thread conducting channel are directed oppositely or countercurrent to the direction of thread travel.

The devices according to the present invention possess an especially good utilization of the energy of the flowing jet stream for purposes of thread treatment, because they are completely closed ofi up to the jet channel for the feed of the gaseous medium and up to the bore or channel through which the thread to be treated runs. In the device of the invention, the yarn can be easily threaded if the feed of the jet medium is shut olf because otherwise the jet medium streaming out of the thread conducting channel with high velocity strongly hinders the leading in of the thread.

In all cases, the preferred treating device of the invention consists of a shaped piece in which the thread conducting channel, jet channel and baflie chamber are formed by boring, drilling, shaping or otherwise worked into the shaped body. In accordance with another special embodiment of the invention, this shaped body is interchangeably inserted into a swinging or adjustable arm having a channel in fluid communication with the jet channel of the insert. This swinging arm with its fluid channel is rotatably mounted upon a tubular feed means having a lateral opening permitting the gas to feed into the fluid channel of the swinging arm when this arm is placed in the open position over the lateral opening. In essence, this arrangement functions as a stopcock wherein a fixed feed line or conduit with a lateral opening serves as a fixed mount for the swinging arm of the jet device such that the feed into the jet channel can be shut off by rotating the swinging arm to a point where its fluid channel no longer engages the lateral opening of the tubular feed mount. In the open position, i.e. where the lateral feed opening and the coaxial feed channel and jet channel in the swinging arm are aligned with each other, the swinging arm is positioned such that the thread conducting channel has its axis in alignment with the general direction of thread travel.

This special means of mounting the device of the invention is illustrated in FIG. 8. Thus, the adjustable swivel arm is rotatably mounted on the cylindrical extension or tube 29 which is fixed in its position on the frame or rigid mounting member 30. The outer surface of the outer feed tube 29 is preferably polished for ease in rotating the arm 28. The hollow cylindrical feed tube 29 with a tapped opening 31 corresponding to the air feed bore has an intermediate lateral opening or bore 32 arranged perpendicularly to the feed bore 31. Then, if the swivel arm 28 lies on the arresting pin 33 fastened to frame 30, the lateral bore 32 coincides exactly with the feed channel 34 in the swivel arm 28. This feed channel 34 is of course further aligned with the jet channel 35 of the insert 36 which also contains the vertical thread channel 37 and the baflie chamber 38. This insert 36 is preferably constructed as a single member consisting of a highly wear-resistant material wherein the jet channel, thread channel and baffle chamber can be easily bored so as to converge upon one another. The baffle chamber 38 is closed off by a threaded stopper 39 which at the same time serves as a means for fastening the highly wear-resistant insert 36 tightly onto the swivel arm 28. A projecting lug 40 can be grasped in order to turn the swivel arm 28 to the offposition 41 as indicated by the broken line rendition of the swivel arm. Thus, by tilting the fluid channel 34 away from the lateral opening 32 in the cylindrical feed line 2, the supply of air is shut off while simultaneously the thread is sharply turned off by the height of the swivel. If desired, this swinging motion of the swivel arm 28 can extend up to a position which permits the removal of the thread by the strong turning motion.

Since the device of the invention provides proportionately greater energy acting on the thread in a small chamber where the turbulent working of the thread occurs, there tends to result a correspondingly greater wear upon the shaped body or insert. For this reason, the jet channel, baffle chamber and thread conducting channel are preferably arranged in an element or shaped body made of a highly wear-resistant material, e.g. ceramic material. Sintered ceramics have proven to be especially suitable where they have a maximum grain size of 2 microns. Also suitable are hard metals and especially steel with a hardness equal to or greater than 60 R WORKING EXAMPLE Thread channel:

Diameter mm 2.6

Length mm 20.0 let channel:

Diameter mm 2.0

Length mm 4.5 Baffle chamber:

Diameter mm 1.9

Depth mm 3.5 Air pressure atii 1.2. Medium ga length cm 4.5

1 Le. 2.2 kg./cn1. abs.

Treated was a nylon 6.6 thread of /48 denier which was drawn through the thread channel with a tension of 0.03 g./denier. Substantially no loops or curls could be observed.

The invention is hereby claimed as follows:

1. An apparatus for the convolution of the individual filaments of at least one multifilament thread or yarn by means of a fluid jet impinging thereon which comprises: a shaped body containing an elongated thread conducting channel therethrough, a jet channel as a nozzle for directing fluid under pressure into said thread conducting channel from one side thereof, and a baflie chamber coaxial with said jet channel on the opposite side of said thread conducting channel, thereby providing a turbulent jet zone within said shaped body at the conjunction of the thread channel, jet channel and battle chamber; said jet channel having a cross-sectional dimension at least equal to or greater than the corresponding cross-sectional dimension 1 l r of the baffle chamber, and the sum of the depth of the baflie chamber and the height of the thread conducting channel at the turbulent jet zone being at least about 2.2 times the smallest cross-sectional dimension of the baflie chamber.

2. An apparatus as claimed in claim 1 wherein the thread run-out portion of said thread channel from the turbulent jet zone to the point of thread exit has a cross sectional dimension not greater than the corresponding smallest cross-sectional dimension of the thread run-in portion of said thread channel.

3. An apparatus as claimed in claim 1 wherein the thread conducting channel is arranged approximately perpendicularly to the common axis of the jet channel and the baflie chamber.

4. An apparatus as claimed in claim 1 wherein the jet channel has a cross-sectional dimension equal to 1 to 2 times the corresponding dimension of the baflle chamber.

5. An apparatus as claimed in claim 1 wherein the sum of the bafiie chamber depth and the thread channel height at the turbulent jet zone is equal to about 2.5 to 10 times the smallest cross-sectional dimension of the baflle chamber.

6. An apparatus as claimed in claim 1 wherein the sum of the baflie chamber depth and the thread channel height at the turbulent jet zone is equal to about 3 to 5 times the smallest cross-sectional dimension of the bafiie chamber.

7. An apparatus as claimed in claim 1 wherein the length of the thread conducting channel is equal to 3 to 30 times the smallest cross-sectional dimension of the baflle chamber.

8. An apparatus as claimed in claim 1 wherein the length of the thread conducting channel is equal to 5 to 20 times the smallest cross-sectional dimension of the baffle chamber.

9. An apparatus as claimed in claim 1 wherein the diameter of the thread channel in the turbulent jet zone is equal to 1.1 to 1.8 times the diameter of the balfle chamber, the length of the entire thread conducting channel is equal to to 30 times the diameter of the baflle chamber, the jet channel diameter is equal to 1.0 to 1.2 times the diameter of the baflie chamber, the length of the jet channel is equal to 1.6 to 4 times the diameter of the battle chamber, the distance between the jet channel mouth and the base of the baffle chamber measured across a cylindrical thread channel at the turbulent jet zone is at least 2.2 times the baffle chamber diameter, and the baifle chamber diameter has a value of about 0.6 to 4 mm.

10. An apparatus as claimed in claim 9 wherein the jet channel length is about 2 to 2.8 times the baifle chamber diameter.

11. An apparatus as claimed in claim 1 wherein the jet channel, thread conducting channel and baffle chamber are arranged in a single shaped body composed of a highly wear-resistant material.

12. An apparatus as claimed in claim 11 wherein the shaped body consists of a sintered ceramic material having a maximum grain size of 2 microns.

13. An apparatus as claimed in claim 11 wherein the shaped body consists of a hard, wear-resistant metal.

14. An apparatus as claimed in claim 13 wherein the metal is steel with a hardness equal to at least 60 R 15. An apparatus as claimed in claim 1 wherein the jet channel contains at least one spiral-shaped insert which partition this channel into at least two adjacent passageways running in a helically shaped path along the length of the channel.

16. An apparatus as claimed in claim 15 wherein said insert is a corkscrew-shaped metal insert exhibiting about /2 to 2 helical windings along the length of the jet channel.

17. An apparatus as claimed in claim 1 wherein said jet channel is inclined for flow of the jet medium against the direction of thread travel at an angle to the thread channel of less than 90 but equal to at least about 60.

18. An apparatus as claimed in claim 1 wherein the thread conducting channel is divided into a thread run-in segment and a cylindrical thread run-out segment with reference to the turbulent jet zone, and the diameter of the thread run-out segment is about 15 to 60% smaller than the largest diameter of the thread run-in segment, and at least that portion of the passageway immediately following the turbulent jet zone in the direction of thread travel is highly smoothed in the transition from larger to smaller diameter.

19. An apparatus as claimed in claim 18 wherein said passageway from the broader to narrower thread channel segments is shaped approximately as a conical segment with an angle of aperture of about 25 to whereby the cone viewed in the direction of thread travel begins at a point removed approximately one-half the jet channel diameter from the jet channel axis at its entry mouth into the thread channel, and said passageway from the cone to the smaller diameter is smoothly rounded and highly polished when taken with the jet channel bore.

20. An apparatus as claimed in claim 18 wherein the thread run-in segment of the thread channel has an entry diameter of about 1.5 to 5 times the bafl'le chamber diameter and constricts conically down to a diameter of about 1.1 to 1.8 times the baflle chamber diameter, and the well smoothed passageway from the conical thread run-in segment to the cylindrical bore of the thread run-out segment lies approximately at the intersection of the thread channel axis and the common axis of the jet channel and baflie chamber.

21. An apparatus as claimed in claim 1 wherein the thread conducting channel, jet channel and baflie chamber are bored into a single shaped body adapted to be mounted for fluid connection with said jet channel.

22. An apparatus as claimed in claim 21 wherein said shaped body is inserted into the adjustable arm of a stopcock which contains a fluid feed conduit for the jet medium, whereby in the open position of the stopcock in which the feed conduit is in fluid connection with said jet channel, the axis of the thread channel of said shaped body lies approximately along the path of thread travel.

23. An apparatus as claimed in claim 22 wherein said stopcock comprises a cylindrical tubular member for carrying a fluid medium with a lateral opening through one side thereof, and an elongated arm with a feed channel arranged to swivel on said cylindrical tubular member from an open position in which the feed channel is in fluid connection with said lateral opening to a closed position in which the feed channel is closed by the wall of said tubular member, said elongated arm having means to receive said shaped body with its jet channel in fluid communication with said feed channel.

24. An apparatus as claimed in claim 1 wherein there is positioned, just prior to the thread entry into thread conducting channel, means to flatten said thread into a narrow band such that the flat surfaces of the band lie perpendicularly to the jet channel axis.

25. An apparatus as claimed in claim 24 wherein said flattening means include two parallel pins arranged one after the other with their longitudinal axes perpendicular to the fixed plane through the axis of the thread channel and the common axis of the jet channel and baflie chamber, the circumferential surface of at least that pin closest to the thread entry into the shaped body resting tangentially on the axis of the thread conducting channel.

26. An apparatus as claimed in claim 25 wherein said flattening means consists of two cylindrical pins of equal diameter lying between about 0.6 and 3 mm. with a clearance between the parallel pins of about 0.3 to 3 mm.

27. An apparatus as claimed in claim 26 wherein the diameter of the pins is about 0.8 to 2 mm. and the clearance therebetween is about 0.8 to 2.4 mm.

.28. An apparatus as claimed in claim 24 wherein a thread flattening pin acting as a final thread guide leading 13 into the entry of the thread conducting channel in said shaped body is arranged with its longitudinal axis at a distance from the thread channel axis equal to the radius of the pin.

29. An apparatus as claimed in claim 24 wherein said means to flatten said thread into a narrow band is arranged at a distance from the entry of the thread conducting channel of about 3 to 15 mm.

30. An apparatus as claimed in claim 24 wherein said means to flatten said thread into a narrow band is arranged at a distance from the entry of the thread conducting channel of about 5 to 12 mm.

References Cited UNITED STATES PATENTS 3,237,269 3/1966 Hawkins 28-1 3,302,386 2/ 1967 Gonsalves et a1 5734 X 3,396,442 8/1968 Gilmore 28-l LOUIS K. RIMRODT, Primary Examiner US. Cl. X.R. 

